Disassembly Xiaomi Redmi 4: a complete guide with photos and expert tips

Why Xiaomi Redmi 4 should be disassembled and when it is needed

Disassembling a smartphone is a procedure that is used in extreme cases. Xiaomi Redmi 4, released in 2016, is still a popular budget device, but over the years its components wear out: battery discharges, the speaker or microphone fails, the power button breaks. In 80% of cases, repairs require full or partial dismantling of the case. However, before taking up the screwdriver, it is worth assessing the risks: improper disassembly can lead to damage to the plumes, loss of leakage (if the device has been in water), or even short-circuiting when the battery is not operated.

Among the most common reasons for dismantling Redmi 4 owners call:

• 🔋 Replacement of the battery (capacity of the original battery — 4100 mAh, but through 3-4 year-on-year 30-50%)
• 🔊 Repair of a speaker or microphone (a common problem after falls or moisture)
• 📱 Replace the broken display (in Redmi 4 the screen is glued to the touchscreen, which complicates the process)
• 🔧 Dust cleaning (cluster of dirt under the back cover can cause overheating)
• 💾 Replacement of slot for SIM-card or memory card (mechanical breakdowns)

It's important to understand that Xiaomi Redmi 4 is not a modular device like the Fairphone, where almost all components are soldered or connected with fragile plumes. If you've never disassembled a smartphone, you'd better go to a service center, but if you decide to act on your own, this guide will help avoid errors.

Preparation for disassembly: tools and precautions

First rule: Never start a disassembly without a full set of tools.

• 🔧 Plastic blade (or mediator) - to separate the back cover
• 🔧 The screwdriver. PH00 (magnetic)
• 🔧 Suction cup for display (optional, but simplifies the task)
• 🔧 Tweezers (for working with small details)
• 🔧 Thermopaste (if you plan to clean the processor)
• 🔧 Isopropyl alcohol (for cleaning contacts)
• 🔧 Antistatic bracelet (protection against static electricity)

Pay special attention to the battery. In Redmi 4, it is glued to the body, and if you do not cleanly separate, you can damage both the battery and the motherboard. If the battery is swollen, it is better to disassemble in gloves and outdoors (the risk of electrolyte leakage).

⚠️ Warning: Before disassembling, be sure to turn off the phone and wait until it cools down (if you were working under load). 2-3 once.

Turn off the phone and remove it. SIM-map

Prepare the workplace (clean surface, good lighting)

Take a picture of the location of the screws before unscrewing

Wear an antistatic bracelet or ground

Prepare containers for small parts (screws, latches)-->

Step-by-step dismantling of Xiaomi Redmi 4: from the back cover to the motherboard

We start with the hardest part, the back cover, and in Redmi 4, it's mounted on the latches and glue, so you have to be careful.

1. Heat the case. Use a hair dryer (~60°C) or put the phone on a warm battery for 3-5 minutes. This will soften the glue.
2. Separate cover. Insert a plastic blade into the gap between the cover and the body (start at the lower right corner where the SIM card is located). Carefully drive the blade around the perimeter, snapping the clamps.
3. Remove the lid. Once all the latches are disconnected, lift the lid at an angle of ~45°. Don't pull sharply, because there are plumes of the fingerprint scanner and antenna underneath.

Under the lid, you'll see:

• 🔋 Battery (stick to the body)
• 📟 Motherboard (fixed with screws)
• 📶 Antenna modules (glued or fixed with latches)
• 🔊 Speaker and microphone (at the bottom)

Then we unscrew the motherboard screws (12 in all, different lengths, remember the location!) and then carefully disconnect the plumes:

1. Display plume (the widest, at the top)
2. Camera plume (thin, right)
3. Power button plume (small, left)

⚠️ Attention: The fingerprint scanner plume is extremely fragile. If it is damaged, the fingerprint unlock function will stop working forever - in Redmi 4, the sensor is soldered into the plume.

Common Mistakes in Disassembly and How to Avoid Them

Even experienced craftsmen sometimes make mistakes that lead to permanent breakdowns, and the most common ones are when working with Redmi 4:

• 🔧 Tangled screws: The phone uses screws of different lengths (from 1.5 mm to 3 mm) If you screw a long screw into an undesignated place, you can damage the board.
• 🔋 A sudden break-off of the battery, which in 60 percent of cases causes the contact pad to rupture, and the battery must be tucked in with a thin plastic card, preheated.
• 📱 Damage to the display plume. It's on top of the battery, and if you're not tidy, it's easy to break. Always disconnect the plume before you take the battery off.
• 💦 Getting moisture on board. Even a drop of sweat can cause corrosion.Work with gloves and avoid wet spaces.

Another critical mistake is the mishandling of flexible plumes. In Redmi 4, they are attached to lock latches. Many beginners try to pull the plume out by force without lifting the latches. The result is a break in contacts. The right order:

1. Raise the black latch (locker) up.
2. Carefully pull the plume parallel to the board (not up!).

1. whether the battery is connected correctly (the contacts should fit tightly).

2. are not damaged plumes (look under the magnifying glass).

3. whether all screws are twisted (unpatched screws can cause short circuits).-->

Replacement of the battery: nuances and recommendations

The battery is the most frequently replaced element in the Redmi 4. The original battery (LB41) has a capacity of 4100 mAh, but after 3-4 years it loses up to 50% of capacity.

• 🔋 Capacity: Optimum 4000-4200 mAh Batteries with declared 5000 mAh are often fakes.
• 🔋 Connector type: Redmi 4 uses a 3-pin connector (not to be confused with the 4-pin connector in Redmi Note 4!).
• 🔋 Manufacturer. Reliable brands: ZOP Power, CAMELION, Remax.

Replacement process:

1. Disconnect the battery plume from the board (it is under a black insulation tape).
2. Heat the body with a hair dryer (~60°C) for 2-3 minutes - this will soften the glue.
3. Put a plastic card on the battery, starting at the top edge. Don't use metal objects!
4. After installing the new battery, be sure to check the voltage with a multimeter (should be 3.7-4.2 V).

⚠️ Warning: If the new battery is quickly discharged, check the current consumption in sleep mode. Norm for Redmi 4 - 10-30 mA. If higher - a problem in the board or software.

💡

After replacing the battery, be sure to calibrate: completely discharge the phone, then charge to 100% without interruptions. Repeat the procedure 2-3 times for the exact operation of the charge controller.

Screen Disassembly: When You Can Do Without Complete Dismantling

The Redmi 4 screen consists of three layers:

1. Protective glass (if installed by the user)
2. Touchscreen (sensory layer)
3. LCD matrix (displays image)

In most cases, only the touchscreen or the glass is affected by a fall, and the matrix remains intact, which saves on repairs.

To determine which layer is damaged:

• 📱 If the screen does not respond to touch, but the image is there – the problem is in the touchscreen or plume.
• 📱 If you see divorces, stripes or broken pixels – damaged matrix.
• 📱 If the screen is completely black, but the phone is working (sounds, vibrations) – check the display plume.

You don't always have to take off the motherboard to replace the glass or the touchscreen.

1. Disconnect the display plume.
2. Heat the screen with a hair dryer (~70°C) to soften the glue.
3. Push the glass with a mediator (start with an angle where there are no plumes).
4. Clean the remains of the glue with isopropyl alcohol.

💡

Use the new glass to be used. UV-Apply a thin layer to avoid bubbles. After gluing, light up the screen. UV-lamp-light 2-3 minute.

Building a phone: how to avoid mistakes

Assembling Redmi 4 after disassembly requires no less care than dismantling.

• 🔧 Check all the plumes. They should be tightly inserted into the connectors, and the locks should be lowered down.
• 🔧 Twisting the screws cross-cross. This prevents the board from skewing.
• 🔧 Don't pull the screws.The carvings in the Redmi 4 body are soft - easy to rip off.
• 🔧 If the phone's been in water, put a silicone lubricant on the seals.

After assembly, perform the test:

1. Connect the charging - check whether the current is coming (the charging indicator should appear).
2. Turn on your phone – make sure the screen responds to touch.
3. Call the phone and check the microphone and speaker.
4. Connect the headphones - a sound test in them.
5. Take a photo - check the camera.

⚠️ Warning: If the phone doesn't turn on after assembly, but it reacts to charging (light bulb), the problem is most likely the plume of the power button or battery contacts.

Frequently asked questions